Orange bright giant · Triangulum Australe
Atria
Also known as: α Trianguli Australis (α TrA), HIP 82273
mag 1.9390 light-years
About
Atria (α Trianguli Australis) is an orange bright giant of magnitude 1.9 in Triangulum Australe, about 390 light-years away.
How to find it
- Atria is in the constellation Triangulum Australe.
- Best evenings: around mid-July it is highest at about 9 pm (10 pm in summer time); a month earlier, two hours later.
- Where on Earth: it is seen well, at least 10° up, from south of 11° N.
When it rises and sets tonight, how high it climbs and how much the Moon gets in the way are worked out in your browser for your place.
What you will see
- EyesEasy, even from town. Its orange-red tint is plain to see.
- Binoculars (10×50)A sharp point; binoculars bring out its colour and the fainter stars around it.
- Telescope (6–8 inch)Still a point of light at any magnification — stars are too far away to show a disc. Low in the sky, bright stars twinkle and flash colours.
Stars look the same in any instrument: brighter and sharper, but never bigger.
Facts
| Proper name | Atria |
|---|---|
| Designation | α Trianguli Australis (α TrA) |
| Hipparcos number | HIP 82273 |
| Type | Orange bright giant |
| Spectral type | K2IIb-IIIa |
| Colour | OrangeB−V colour index 1.45 |
| Magnitude | 1.9The smaller the number, the brighter. |
| Distance | 390 light-yearsThe light you see left it around 1640. |
| Proper motion | 0.037″ per year across the sky |
| Constellation | Triangulum Australe |
| Right ascension (J2000) | 16h 48m 39.9s |
| Declination (J2000) | −69° 01′ 40″ |
More in Triangulum Australe
Sources and credits
Star data: HYG Database by David Nash, CC BY-SA 4.0. All data sources →